Diaper having plural upstanding leg cuffs

ABSTRACT

A disposable absorbent article such as a diaper. The diaper has dual upstanding inner and outer barrier leg cuffs, and preferably gasket cuffs. The inner barrier leg cuffs are liquid pervious, while the outer barrier leg cuffs are liquid impermeable. The inner barrier leg cuffs are preferably spaced apart from one another sufficient to allow urine and fecal material to be deposited therebetween. Each outer barrier leg cuff is preferably spaced properly from the inner barrier leg cuff so as to allow the leg cuffs to function independently, yet maintain a proper target area for the deposition of urine and fecal material.

FIELD OF THE INVENTION

This invention is related to disposable absorbent articles, particularlyto disposable absorbent articles such as diapers, which receive fecalmaterial, and more particularly to diapers having upstanding leg cuffs.

BACKGROUND OF THE INVENTION

Disposable absorbent articles, such as diapers, are well known in theart. These articles address the consumers' demands for increasedconvenience. In particular, disposable absorbent articles which minimizecleaning of the wearer after the article is soiled provide convenience.A particularly desired feature in such diapers is the prevention orminimization of leakage of urine and fecal material received by thediaper.

Several attempts in the art have been very successful at reducingleakage from the diaper. One early attempt provided an elasticcontracting member, which elastically contracted the outer side portionof the diaper. This highly successful advance in the art provided agasket leg cuff. The gasket leg cuff was disposed in the plane of thediaper. The next attempt provided a diaper having elasticized flaps,known as barrier leg cuffs. Barrier leg cuffs stand up out of the planeof the diaper and thereby improve containment. Yet other attempts in theart included diapers with dual cuffs, including both a gasket leg cuffand a barrier leg cuff. Yet other advances in the art provided leg cuffswith relatively low contact forces against the skin of the wearer atrelatively high elongations, minimizing wearer discomfort.

Examples of such attempts in the art can be found in commonly assignedU.S. Pat. Nos. 3,860,003 issued Jan. 14, 1975 to Buell; 4,695,278 issuedSep. 22, 1987 to Lawson; 4,909,803 issued Mar. 20, 1990 to Aziz et al.;and 5,032,120 issued Jul. 16, 1991 to Freeland et al., which patents areincorporated herein by reference.

However, there is a need in the art for diapers which further reduceleakage. There is further a need in the art for such a diaper whichminimizes leakage of fecal material from the leg region.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view, shown partially in cutaway, of a diaperaccording to the present invention.

FIG. 2 is an instantaneous vertical sectional view taken along lines2--2 of FIG. 1.

SUMMARY OF THE INVENTION

The invention comprises a diaper having a longitudinal centerline and alateral centerline orthogonal to the longitudinal centerline. The diaperhas a liquid pervious topsheet, a liquid impermeable backsheet at leastpartially peripherally joined to the topsheet, and an absorbent coreintermediate the topsheet and the backsheet.

Upstanding from the plane of the topsheet are two generallylongitudinally oriented liquid impervious outer barrier leg cuffs. Oneof the outer barrier leg cuffs is disposed on each side of thelongitudinal centerline. Also upstanding from the plane of the topsheetare two generally longitudinally oriented liquid pervious inner barrierleg cuffs. One of each of the inner barrier leg cuffs is also disposedon each side of the longitudinal centerline. Each of the inner barrierleg cuffs is disposed between the corresponding outer barrier leg cuffand the longitudinal centerline. Each of the outer barrier leg cuffs isoutboard of and preferably spaced apart from the corresponding innerbarrier leg cuff 0.5 to 2.0 inches.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "absorbent article" refers to devices whichabsorb and contain body exudates and are placed against or in proximityto the body of the wearer to absorb and contain discharges. The term"disposable" describes absorbent articles not intended to be launderedor otherwise restored or reused (i.e., they are intended to be discardedafter a single use and preferably recycled, composted, or otherwisedisposed of in an environmentally compatible manner). A "unitary"absorbent article refers to an article formed of separate pans unitedtogether to form a coordinated entity that does not require separatemanipulative parts, like a separate holder and liner. A preferredembodiment of a disposable absorbent article of the present invention isthe unitary disposable absorbent article, diaper 20, shown in FIG. 1. Asused herein the term "diaper" refers to a disposable absorbent articlegenerally worn by infants and incontinent persons about the lower torso.It should be understood, however, that the present invention is alsoapplicable to other disposable absorbent articles such as incontinencebriefs, incontinence undergarments, and diaper holders and liners.

FIG. 1 is a plan view of diaper 20 of the present invention in its flat,uncontracted state (with elastic induced contraction pulled out, andportions of the structure cut away to more clearly show the constructionof the diaper 20). The portion of the diaper 20 which faces or contactsthe wearer, i.e., the inner surface, is oriented towards the viewer. Thediaper 20 has a longitudinal centerline O--O and a lateral centerlineA--A. As used here in the longitudinal centerline O--O or dimension isaligned front to back and bisects the standing wearer into left andright body halves. The lateral centerline A--A or dimension isorthogonal the longitudinal centerline O--O and lies within the plane ofthe diaper 20. The Z-direction is orthogonal to both the longitudinaland lateral directions and comes out of the plane of the diaper 20.

The diaper 20 has a chassis 22 comprising a liquid pervious topsheet 24,a liquid impermeable backsheet 26 at least partially peripherally joinedto the topsheet 24, and an absorbent core 28 between the topsheet 24 andthe backsheet 26. The topsheet 24 has an inwardly oriented surface whichis oriented towards the core 28, and an outwardly oriented surface whichis oriented towards and/or contacts the wearer. Upstanding from theplane of the top sheet 24 are a set of inner barrier leg cuffs 30, and aset of outer barrier leg cuffs 32. Outboard of the outer barrier legcuffs 32 and in line within the plane of the diaper 20 are gasket cuffs34. As used herein, "outboard" refers to either lateral direction whichis oriented away from the longitudinal centerline O--O.

The diaper 20 may also include tape fasteners 36 positioned in the rearwaist region for fastening the diaper 20 about the wearer. The diaper 20can also have an elastic waistband (not shown). Commonly assigned U.S.Pat. Nos. 3,848,594 issued Nov. 19, 1974 to Buell; Re. B1 4,662,875issued May 5, 1987 to Hirotsu et al. are incorporated herein byreference to illustrate tape fasteners 36; and 4,515,959 issued May 17,1985 to Kiev; and 4,816,025 issued Mar. 28, 1989 to Foreman, areincorporated herein by reference to illustrate elasticized waistfeatures.

The top sheet 24 and backsheet 26 of the diaper 20 have longitudinal andlateral dimensions generally larger than those of the absorbent core 28,so that the topsheet 24 and backsheet 26 may extend beyond the core 28to thereby form the periphery 29 of the diaper 20. The embodimentdescribed herein is suitable for a wearer weighing about 7.3 to about12.7 kilograms (16 to 28 pounds). It will be understood that if thediaper 20 is intended for use with larger or smaller wearers, includingadults, or if the diaper 20 is closed in a training pants style, thediaper 0, including the inner and outer barrier leg cuffs 30, 32, mayhave to be scaled accordingly.

Examining the components of the diaper 20 in more detail, the topsheet24 and backsheet 26 are generally coextensive and at least partiallyperipherally joined. As used herein, the term "joined" refers to thecondition where a first member or component is affixed or connected to asecond member or component, either directly or indirectly where thefirst member or component is directly affixed to the second member orcomponent, or connected to an intermediate member or component which inturn is affixed or connected to the second member or component.Components which are "joined" are intended to remain affixed orconnected throughout the intended life of the diaper 20 and not to beseparated unless and until the diaper 20 is discarded and as may benecessary for environmentally compatible disposal. Components which are"joined" cannot be separated without tearing or gross deformation of oneor both components.

The topsheet 24 refers to any liquid pervious facing of the diaper 20which contacts the skin of the wearer and prevents substantial contactof the absorbent core 28 with the skin of the wearer. The topsheet 24 iscompliant, tactilely pleasant, and non-irritating to the skin.

A suitable topsheet 24 may be manufactured from porous foams, aperturedplastic films, natural fibers, synthetic fibers, or a combinationthereof. A particularly preferred topsheet 24 comprises polypropylenefibers and may be manufactured as a nonwoven web of spunbonded, carded,wet laid, melt blown, hydroentangled fibers. A particularly preferredtopsheet 24 is carded and thermally bonded to have a basis weight of 14to 25 grams per square meter. A suitable topsheet 24 is marketed byVeratec Inc., Division of International Paper Company, of Walpole, Mass.under the designation P-8.

The backsheet 26 is impermeable to fluids such as urine and preventsfluids absorbed and contained by the core 28 from wetting theundergarments. As used herein, the "backsheet" refers to any barrierdisposed outwardly of the core 28 as the diaper 20 is worn and whichcontains absorbed liquid within the diaper 20. The backsheet 26 ispreferably manufactured from a thin plastic film, although otherflexible, liquid impermeable materials may be used. As used herein, theterm "flexible" refers to materials which are compliant and will readilyconform to the general shape of the human body.

The backsheet 26 may be a polyolefinic film, such as polyethylene,having a thickness of about 0.01 to 0.05 millimeters. A suitablebacksheet 26 can be made from a blend of 45 to 90 percent LLDP and about10 to 55 percent polypropylene. Exemplary backsheet films are sold byTredegar Industries of Terre Haute, Ind. under the designation RR8220and RR5475.

The topsheet 24 and backsheet 26 may be joined by any means well knownin the art, such as adhesive bonding or heat sealing. A particularlypreferred method of joining the topsheet 24 and backsheet 26 is with hotmelt adhesives such as are manufactured by Century Adhesives, Inc. ofColumbus, Ohio and marketed as Century 5227, or BL1258 adhesive sold bythe H. B. Fuller Company of St. Paul, Minn., or H2031 available from theFindley Adhesives Company of Elmgrove, Wisc.

As used herein, the term "core" refers to any component of the diaper 20intermediate the topsheet 24 and backsheet 26 and used for absorbing andretaining body exudates. The core 28 may be encased by one or morelayers of tissue (not shown).

The absorbent core 28 may be made from a variety of materials such ascomminuted wood pulp and may further contain particulate or fibrousabsorbent gelling materials as are commonly known in the art. Theabsorbent core 28 may be made in accordance with the teachings ofcommonly assigned U.S. Pat. Nos. 4,610,678 issued Sep. 9, 1986 toWeisman et al.; 5,137,537 issued Aug. 11, 1992 to Herron et al.; and5,147,345 issued Sep. 15, 1992 to Young et al., which patents areincorporated herein by reference. Absorbent gelling materials, ifdesired, may be made in accordance with commonly assigned U.S. Pat. Re.32,649, reissued Apr. 19, 1988 to Brandi et al.

Referring to FIG. 2, the inner barrier leg cuffs 30 may, in part,overlie the core 28 and are generally longitudinally oriented.Preferably each inner barrier leg cuff 30 is laterally spaced a distanceof 2.0 to 3.5 inches from the other inner barrier leg cuff 30. Suchspacing is taken at the proximal edges 30B of the inner barrier legcuffs 30. Generally, for the embodiment described herein, this spacingis critical for proper performance of the diaper 20. Such a spacing isnecessary to allow sufficient room for urine and fecal material to bedeposited on the topsheet 24 at a position intermediate the innerbarrier leg cuffs 30. Therefore, the inner barrier leg cuffs 30 shouldnot be spaced any closer together than this range. Likewise, the innerbarrier leg cuffs 30 should not be spaced too far apart, otherwise theinner barrier leg cuffs 30 will be too close to the outer barrier legcuffs 32, as discussed below.

The inner barrier leg cuffs 30 are preferably elastically contractibledue to elastic strands 30A joined to the inner barrier leg cuffs 30. Theelastic strands 30A may be made using any type of elastic as is wellknown in the art. Of course, elastic strands 30A, 32A includeelastomeric films, elastomeric adhesives, as well as elastic strands,and combinations thereof. The inner barrier leg cuffs 30 may have anelasticized length in the longitudinal direction of about 8 to 15inches. The elastic strands 30 may have a force of 10 to 30 grams, andpreferably 15 to 25 grams, at 85 percent elongation. Preferably theinner barrier leg cuff 30 extends 0.5 to 1.25 inches above the plane ofthe topsheet 24 to a distal edge.

The inner barrier leg cuffs 30 are preferably hydrophilic and liquidpervious. These material properties are critical in that they allowurine deposited on the topsheet 24 to laterally migrate through theinner barrier leg cuffs 30 so that full utilization of the capacity ofthe absorbent core 28 is possible. Conversely, if the inner barrier legcuffs 30 were liquid impervious, urine would pool between the innerbarrier leg cuffs 30, irritating the skin of the wearer and may lead topremature leakage. An additional benefit of a hydrophilic pervious innerbarrier leg cuff 30 is that low viscosity fecal material which contactsthe inner barrier leg cuff 30 may be partitioned into solid componentswhich are contained between the inner barrier leg cuffs 30 and liquidcomponents which permeate the inner barrier leg cuffs 30. Bypartitioning the low viscosity fecal material in this manner, thelikelihood of it leaking is reduced.

Preferably the inner barrier leg cuffs 30 are made of a nonwovenmaterial, as is available from the Veratec Company of Walpole, Mass. Theinner barrier leg cuffs 30 may be adhesively joined to the topsheet 24as is well known in the art. The distal end of the inner barrier legcuff may be joined to the topsheet 24 at the waist margins of the diaper20, as shown. The upstanding portion of the inner barrier leg cuff 30may be liquid impervious, in part, so long as urine can pass through atleast a portion thereof, and the proximal edge 30B does not preventurine from passing into the topsheet 24.

Each outer barrier leg cuff 32 is preferably spaced 0.5 to 2.0 incheslaterally outboard (i.e., away from the longitudinal centerline O--O) ofits corresponding inner barrier leg cuff 30. Such spacing is taken atthe proximal edge 32B of the outer barrier leg cuff 32. Inner barrierleg cuffs 30, outer barrier leg cuffs 32, and gasket cuffs 34 are saidto be "corresponding" if they are disposed on the same side of thelongitudinal centerline O--O.

It is, of course, recognized that the inner and outer barrier leg cuffs30, 32 may not always be straight and parallel, as shown. Instead, oneset of barrier leg cuffs 30, 32 may be longitudinally oriented as shown,and the other set of barrier leg cuffs 32, 30 be in angular relationshiptherewith. For purposes of the present invention, the spacing criterionis met if at least 33 percent of the upstanding portions of the innerand outer barrier leg cuffs 30, 32 fall within the aforementioned rangeof 0.5 to 2.0 inches. Although a minimum of 50 percent effective spacingis preferred, at least 75 percent is more preferred. Preferably, theaforementioned spacing is met at the rear portion of the diaper 20because this is most typically where fecal material is loaded.

This spacing between the inner and outer barrier leg cuffs 30, 32 iscritical. If the inner and outer barrier leg cuffs 30, 32 are spaced tooclose together, they will function as a single barrier leg cuff and notbe effective at reducing leakage. Likewise, the distal ends of the innerand outer barrier leg cuffs 30, 32 must be separated, and not joinedtogether, otherwise they will function like a single leg cuff.Conversely, the outer barrier leg cuff 32 cannot be spaced further fromthe inner barrier leg cuff 30 than the constraints imposed by theperiphery 29 of the diaper 20. As noted above, once the periphery 29 ofthe diaper 20 is fixed, the inner barrier leg cuffs 30 (as measuredbetween the proximal edges 30) cannot be moved closer together,otherwise the urine and fecal material may be deposited on the innerbarrier leg cuffs 30, or between the inner and outer barrier leg cuffs30, 32. If either occurs, leakage is more likely to result.

The outer barrier leg cuffs 32 are preferably elastically contractibledue to elastic strands 32A joined to the outer barrier leg cuffs 32. Theelastic strands 32A may be made using any type of elastic as is wellknown in the art. The outer barrier leg cuffs 32 may have an elasticizedlength taken in the longitudinal direction of about 8 to 15 inches, andhave a force of 30 to 65 grams, and preferably 40 to 50 grams at 85percent elongation.

It is important that the outer barrier leg cuffs 32 have a greatercontractive force under a given elongation than the inner barrier legcuffs 30, so that a tighter seal is formed at the leg of the wearer.Additionally, the inner leg cuffs 30 typically intercept the skin of thewearer at a position of the body more prone to red marking, and thediscomfort attendant therewith. Therefore, less force should be appliedby the inner barrier leg cuff 30 than the outer barrier leg cuff 32.

Preferably the outer barrier leg cuffs 32 extend 0.75 to 2.0 inchesabove the plane of the topsheet 24. The outer barrier leg cuffs 32preferably extend further in the Z-direction than the inner barrier legcuffs 30, so that overflow past the inner barrier leg cuffs 30 does notreach a second barrier leg cuff 32 of the same height and allow leakage.Also, this greater Z-direction extent is necessary to accommodate thecurvature of the buttocks of the wearer.

It is critical that the outer barrier leg cuff 32 be hydrophobic and/orliquid impervious in order that any urine, low viscosity fecal material,or components of low viscosity fecal material which permeated the innerbarrier leg cuff 30 is retained inboard (i.e., towards the longitudinalcenterline O--O) of the outer barrier leg cuffs 32 so that leakage doesnot result. The outer barrier leg cuffs 32 may be made of a nonwovenmaterial such as is available from Fiberweb Company of Simpsonville,S.C.

Optionally, a gasket cuff 34 is included in the diaper 20. The gasketcuff 34 may be spaced inboard or outboard of the outer barrier leg cuff32 so long as the gasket cuff 34 is outboard of the inner barrier legcuff 30. Preferably the gasket cuff 34 is outboard of the outer barrierleg cuff 32, so that the periphery 29 of the diaper 20 more readilyconforms to the shape of the buttocks, and so that it is spaced farenough from the absorbent core 28 to be effective. In an alternativeembodiment (not shown), the gasket cuff 34 may be positioned between theinner barrier leg cuff 30 and the outer barrier leg cuff 32. While thepresent invention does allow for bringing the gasket cuff 34 to withinless than 0.75 inches of the edge of the absorbent core 28, contrary toimportant teachings in the prior art, such a spacing is generally notpreferred.

What is claimed is:
 1. A diaper having a longitudinal centerline, alateral centerline orthogonal thereto, and a Z-direction perpendicularto said longitudinal centerline and said lateral centerline said diapercomprising:a liquid pervious topsheet; a liquid imperious backsheet atleast partially peripherally joined to said topsheet; an absorbent coreintermediate said topsheet and said backsheet; two generallylongitudinally oriented outer barrier leg cuffs, upstanding from theplane of said topsheet, one of said outer barrier leg cuffs beingdisposed on each side of said longitudinal centerline; two generallylongitudinally oriented inner barrier leg cuffs upstanding from theplane of said topsheet, one of said inner barrier leg cuffs beingdisposed on each side of said longitudinal centerline, so that each saidinner barrier leg cuff is disposed on the same side of said longitudinalcenterline as one of said outer barrier leg cuffs corresponding thereto,each said corresponding outer barrier leg cuff and said correspondinginner barrier leg cliff being spaced apart 0.5 inches to 2.0 inches,said outer barrier leg cuffs having a greater extent in the Z-directionthan said inner barrier leg cuffs; and two gasket cuffs lying within theplane of said diaper, one said gasket cuff being disposed on each sideof said longitudinal centerline.
 2. A diaper according to claim 1wherein said inner barrier leg cuffs are spaced apart 2.0 to 3.5 inches.3. A diaper according to claim 1 wherein each said gasket cuff isdisposed outboard of said inner barrier leg cuff disposed on the sameside of said longitudinal centerline as said gasket cuff.
 4. A diaperaccording to claim 3 wherein each said gasket leg cuff is disposedoutboard of said outer barrier leg cuff disposed on the same side ofsaid longitudinal centerline as said gasket cuff.
 5. A diaper accordingto claim 4 wherein said inner barrier leg cuffs have an elastic force at85 percent elongation of 15 to 25 grams.
 6. A diaper according to claim4 wherein said outer barrier leg cuffs have an elastic force at 85percent elongation of 40 to 50 grams.
 7. A diaper having a longitudinalcenterline, a lateral centerline orthogonal thereto, and a Z-directionperpendicular to said longitudinal centerline and said lateralcenterline said diaper comprising;a liquid pervious topsheet; a liquidimpervious backsheet at least partially peripherally joined to saidtopsheet; an absorbent core intermediate said topsheet and saidbacksheet; two generally longitudinally oriented liquid impervious outerbarrier leg cuffs, upstanding from the plane of said topsheet, one ofsaid outer barrier leg cuffs being disposed on each side of saidlongitudinal centerline; two generally longitudinally oriented liquidpervious inner barrier leg cuffs upstanding from the plane of saidtopsheet, one of said inner barrier leg cuffs being disposed on eachside of said longitudinal centerline, so that each said inner barrierleg cuff is disposed on the same side of said longitudinal centerline asone of said outer barrier leg cuffs corresponding thereto, said .outerbarrier leg cuffs having a greater extent in the Z-direction than saidinner barrier leg cuffs; and two gasket cuffs lying within the plane ofsaid diaper, one said gasket cuff being ..disposed on each side of saidlongitudinal centerline.
 8. A diaper according to claim 7 wherein saidinner barrier leg cuffs are spaced apart 2.0 to 3.5 inches.
 9. A diaperaccording to claim 8 whrein said outer barrier leg cuffs arehydrophobic.
 10. A diaper according to claim 9 wherein said innerbarrier leg cuffs have an elastic force at 85 percent elongation of 15to 25 grams.
 11. A diaper according to claim 10 wherein said outerbarrier leg cuffs have an elastic force at 85 percent elongation of 40to 50 grams.
 12. A diaper according to claim 8 wherein said innerbarrier leg cuffs are hydophilic.
 13. A diaper according to claim 7wherein each said gasket leg cuff is disposed outboard of said innerbarrier leg cuff disposed on the same side of said longitudinalcenterline as said gasket cuff.